src/icmp/IcmpSquid.cc

   1 /*
   2  * $Id$
   3  *
   4  * DEBUG: section 37    ICMP Routines
   5  * AUTHOR: Duane Wessels, Amos Jeffries
   6  *
   7  * SQUID Web Proxy Cache          http://www.squid-cache.org/
   8  * ----------------------------------------------------------
   9  *
  10  *  Squid is the result of efforts by numerous individuals from
  11  *  the Internet community; see the CONTRIBUTORS file for full
  12  *  details.   Many organizations have provided support for Squid's
  13  *  development; see the SPONSORS file for full details.  Squid is
  14  *  Copyrighted (C) 2001 by the Regents of the University of
  15  *  California; see the COPYRIGHT file for full details.  Squid
  16  *  incorporates software developed and/or copyrighted by other
  17  *  sources; see the CREDITS file for full details.
  18  *
  19  *  This program is free software; you can redistribute it and/or modify
  20  *  it under the terms of the GNU General Public License as published by
  21  *  the Free Software Foundation; either version 2 of the License, or
  22  *  (at your option) any later version.
  23  *
  24  *  This program is distributed in the hope that it will be useful,
  25  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  26  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27  *  GNU General Public License for more details.
  28  *
  29  *  You should have received a copy of the GNU General Public License
  30  *  along with this program; if not, write to the Free Software
  31  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
  32  *
  33  */
  34
  35 #include "squid.h"
  36 #include "comm.h"
  37 #include "comm/Loops.h"
  38 #include "icmp/IcmpSquid.h"
  39 #include "icmp/net_db.h"
  40 #include "ip/tools.h"
  41 #include "SquidTime.h"
  42
  43 // Instance global to be available in main() and elsewhere.
  44 IcmpSquid icmpEngine;
  45
  46 #if USE_ICMP
  47
  48 #define S_ICMP_ECHO     1
  49 #if DEAD_CODE
  50 #define S_ICMP_ICP      2
  51 #endif
  52 #define S_ICMP_DOM      3
  53
  54 static void * hIpc;
  55 static pid_t pid;
  56
  57 #endif /* USE_ICMP */
  58
  59
  60 IcmpSquid::IcmpSquid() : Icmp()
  61 {
  62     ; // nothing new.
  63 }
  64
  65 IcmpSquid::~IcmpSquid()
  66 {
  67     Close();
  68 }
  69
  70
  71 #if USE_ICMP
  72
  73 void
  74 IcmpSquid::SendEcho(Ip::Address &to, int opcode, const char *payload, int len)
  75 {
  76     static pingerEchoData pecho;
  77     int x, slen;
  78
  79     /** \li Does nothing if the pinger socket is not available. */
  80     if (icmp_sock < 0) {
  81         debugs(37, 2, HERE << " Socket Closed. Aborted send to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
  82         return;
  83     }
  84
  85     /** \li  If no payload is given or is set as NULL it will ignore payload and len */
  86     if (!payload)
  87         len = 0;
  88
  89     /** \li Otherwise if len is 0, uses strlen() to detect length of payload.
  90      \bug This will result in part of the payload being truncated if it contains a NULL character.
  91      \bug Or it may result in a buffer over-run if the payload is not nul-terminated properly.
  92      */
  93     else if (payload && len == 0)
  94         len = strlen(payload);
  95
  96     /** \li
  97      \bug If length specified or auto-detected is greater than the possible payload squid will die with an assert.
  98      \todo This should perhapse be reduced to a truncated payload? or no payload. A WARNING is due anyway.
  99      */
 100     assert(len <= PINGER_PAYLOAD_SZ);
 101
 102     pecho.to = to;
 103
 104     pecho.opcode = (unsigned char) opcode;
 105
 106     pecho.psize = len;
 107
 108     if (len > 0)
 109         memcpy(pecho.payload, payload, len);
 110
 111     slen = sizeof(pingerEchoData) - PINGER_PAYLOAD_SZ + pecho.psize;
 112
 113     debugs(37, 2, HERE << "to " << pecho.to << ", opcode " << opcode << ", len " << pecho.psize);
 114
 115     x = comm_udp_send(icmp_sock, (char *)&pecho, slen, 0);
 116
 117     if (x < 0) {
 118         debugs(37, 1, HERE << "send: " << xstrerror());
 119
 120         /** \li  If the send results in ECONNREFUSED or EPIPE errors from helper, will cleanly shutdown the module. */
 121         /** \todo This should try restarting the helper a few times?? before giving up? */
 122         if (errno == ECONNREFUSED || errno == EPIPE) {
 123             Close();
 124             return;
 125         }
 126         /** All other send errors are ignored. */
 127     } else if (x != slen) {
 128         debugs(37, 1, HERE << "Wrote " << x << " of " << slen << " bytes");
 129     }
 130 }
 131
 132 // static Callback to wrap the squid-side ICMP handler.
 133 // the IcmpSquid::Recv cannot be declared both static and virtual.
 134 static void
 135 icmpSquidRecv(int unused1, void *unused2)
 136 {
 137     icmpEngine.Recv();
 138 }
 139
 140 void
 141 IcmpSquid::Recv()
 142 {
 143     int n;
 144     static int fail_count = 0;
 145     pingerReplyData preply;
 146     static Ip::Address F;
 147
 148     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 149     memset(&preply, '\0', sizeof(pingerReplyData));
 150     n = comm_udp_recv(icmp_sock,
 151                       (char *) &preply,
 152                       sizeof(pingerReplyData),
 153                       0);
 154
 155     if (n < 0 && EAGAIN != errno) {
 156         debugs(37, 1, HERE << "recv: " << xstrerror());
 157
 158         if (errno == ECONNREFUSED)
 159             Close();
 160
 161         if (errno == ECONNRESET)
 162             Close();
 163
 164         if (++fail_count == 10)
 165             Close();
 166
 167         return;
 168     }
 169
 170     fail_count = 0;
 171
 172     /** If its a test probe from the pinger. Do nothing. */
 173     if (n == 0) {
 174         return;
 175     }
 176
 177     F = preply.from;
 178
 179     F.SetPort(0);
 180
 181     switch (preply.opcode) {
 182
 183     case S_ICMP_ECHO:
 184         debugs(37,4, HERE << " ICMP_ECHO of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 185         break;
 186
 187     case S_ICMP_DOM:
 188         debugs(37,4, HERE << " DomainPing of " << preply.from << " gave: hops=" << preply.hops <<", rtt=" << preply.rtt);
 189         netdbHandlePingReply(F, preply.hops, preply.rtt);
 190         break;
 191
 192     default:
 193         debugs(37, 1, HERE << "Bad opcode: " << preply.opcode << " from " << F);
 194         break;
 195     }
 196 }
 197
 198 #endif /* USE_ICMP */
 199
 200 void
 201 IcmpSquid::DomainPing(Ip::Address &to, const char *domain)
 202 {
 203 #if USE_ICMP
 204     debugs(37, 4, HERE << "'" << domain << "' (" << to << ")");
 205     SendEcho(to, S_ICMP_DOM, domain, 0);
 206 #endif
 207 }
 208
 209 int
 210 IcmpSquid::Open(void)
 211 {
 212 #if USE_ICMP
 213     const char *args[2];
 214     int rfd;
 215     int wfd;
 216     Ip::Address localhost;
 217
 218     /* User configured disabled. */
 219     if (!Config.pinger.enable) {
 220         Close();
 221         return -1;
 222     }
 223
 224     args[0] = "(pinger)";
 225     args[1] = NULL;
 226     localhost.SetLocalhost();
 227
 228     /*
 229      * Do NOT use IPC_DGRAM (=IPC_UNIX_DGRAM) here because you can't
 230      * send() more than 4096 bytes on a socketpair() socket (at
 231      * least on FreeBSD).
 232      */
 233     pid = ipcCreate(IPC_UDP_SOCKET,
 234                     Config.pinger.program,
 235                     args,
 236                     "Pinger Socket",
 237                     localhost,
 238                     &rfd,
 239                     &wfd,
 240                     &hIpc);
 241
 242     if (pid < 0)
 243         return -1;
 244
 245     assert(rfd == wfd);
 246
 247     icmp_sock = rfd;
 248
 249     fd_note(icmp_sock, "pinger");
 250
 251     Comm::SetSelect(icmp_sock, COMM_SELECT_READ, icmpSquidRecv, NULL, 0);
 252
 253     commUnsetFdTimeout(icmp_sock);
 254
 255     debugs(37, 1, HERE << "Pinger socket opened on FD " << icmp_sock);
 256
 257     /* Tests the pinger immediately using localhost */
 258     if (Ip::EnableIpv6)
 259         SendEcho(localhost, S_ICMP_ECHO, "ip6-localhost");
 260     if (localhost.SetIPv4())
 261         SendEcho(localhost, S_ICMP_ECHO, "localhost");
 262
 263 #if _SQUID_MSWIN_
 264
 265     debugs(37, 4, HERE << "Pinger handle: 0x" << std::hex << hIpc << std::dec << ", PID: " << pid);
 266
 267 #endif /* _SQUID_MSWIN_ */
 268     return icmp_sock;
 269 #else /* USE_ICMP */
 270     return -1;
 271 #endif /* USE_ICMP */
 272 }
 273
 274 void
 275 IcmpSquid::Close(void)
 276 {
 277 #if USE_ICMP
 278
 279     if (icmp_sock < 0)
 280         return;
 281
 282     debugs(37, 1, HERE << "Closing Pinger socket on FD " << icmp_sock);
 283
 284 #if _SQUID_MSWIN_
 285
 286     send(icmp_sock, (const void *) "$shutdown\n", 10, 0);
 287
 288 #endif
 289
 290     comm_close(icmp_sock);
 291
 292 #if _SQUID_MSWIN_
 293
 294     if (hIpc) {
 295         if (WaitForSingleObject(hIpc, 12000) != WAIT_OBJECT_0) {
 296             getCurrentTime();
 297             debugs(37, 0, HERE << "WARNING: (pinger," << pid << ") didn't exit in 12 seconds");
 298         }
 299
 300         CloseHandle(hIpc);
 301     }
 302
 303 #endif
 304     icmp_sock = -1;
 305
 306 #endif
 307 }